Question

5. Find the equation of a circle whose center is at (5, -8) and radius 8.

Answer 1

Answer:

$x^{2} + y^{2} -10x -16y + 39$

Step-by-step explanation:-

The equation used to find the equation of circle is :-

$(x-a)^{2} + (y-b)^{2} = radius^{2}$

'a' means the x coordinate of the circle, 'b' means y coordinate of the circle.

In the question, it's given that the coordinates of the circle are (5, -8) and radius is 8cm.

So, 'a' will be 5 and 'b' will be -8

So,

$(x-5)^{2} + (y--8)^{2} = 8^{2}$

$(x-5)^{2} + (y+8)^{2} = 64$

$x^{2} - 10x + 25 + y^{2} - 16y + 64$

$x^{2} + y^{2} -10x -16y + 64 - 25$

= $x^{2} + y^{2} -10x -16y + 39$